1. Field of the Invention
The present invention relates generally to a power management and charger circuitry, and more particularly, to a circuit of integrated power management and charger unit applied to the battery powered apparatus.
2. Background
For any battery-powered devices, it typically requires a separate charger for connection to an adaptor during battery recharge. An adaptor provides alternate current (AC) to direct current (DC) conversion. In order to properly charge the battery, a charger is typically used.
U.S. Pat. No. 5,534,765, issued to Naokawa et al. entitled “Battery with memory for storing charge procedure” discloses a charger for supplying charge current and voltage and a battery having a memory for storing charge parameters, where the block diagram of an example design for a power management and charge unit is shown in FIG. 1. At the highest functional level, it includes a charger unit 110, a battery 120 and a battery-powered device. The charger unit further includes a micro-processor, Read Only Memories (ROM), Random Access Memories (RAM), and programmable current and voltage sources. Various charging configurations (for various charging current) are stored in the RAM/ROM. While the device is being charged, the input of the charger unit 110 is connected to an adaptor. The output of the charger unit 110 is connected to the input of the battery. In this design, the characteristics of the battery 120 are stored in the memory 122 of the battery 120. While charging, the characteristic of the battery 120 is first read (by the controller 130) from the battery memory 122. And based on the battery characteristics, proper charging current is supplied (by the charger unit 110) to the battery while charging. And the “output of the battery” (123 and 124 in FIG. 1) is connected to the battery-powered device. However, in such designs, the battery powered device is a separate unit.